1. Field of Invention
This invention relates generally to the structure, design and manufacturing of side shooter fluid drop ejectors.
2. Description of Related Art
Fluid ejection systems, such as ink jet printers, typically employ an array of electrically controllable ejectors in the ejector head that are usable to eject fluid drops onto a receiving medium, such as paper. In a thermal fluid ejection system, electric current is applied to a resistive heater in the ejector head, vaporizing fluid in a fluid chamber. The rapid expansion of fluid vapor causes a fluid drop to be ejected through a fluid path and out the ejector opening or nozzle. Alternatively, non-thermal fluid ejection systems rely on an over-pressure due to mechanical compression caused by a piezoelectric element or mechanical pressure pulse to selectively eject a fluid drop from the ejector nozzle.
Fluid ejection heads utilizing thermal or mechanical ejectors are typically manufactured in a modular manufacturing process, where various layers that make up the ejector head are formed separately and then bonded together. The bonded layers arc then diced into individual fluid ejector head units. For example, in a typical thermal fluid ejection head, a bottom layer, formed using a silicon substrate, contains a plurality of nozzle heating elements, one for each ejector nozzle, as well as the heater electronics and transducers for the heating elements. A polymer layer is placed over the heater layer and is used to form the fluid channels and nozzle walls. Finally, a channel wafer is placed over the polymer layer and is used to form ink inlets, ink reservoirs and nozzle roofs.
The conventional fluid ejector head architecture offers precise control over the nozzle size but limits the nozzle geometry to geometric, straight-walled, cornered shapes such as triangles, squares, or rectangles. Also, bonding and dicing of the sandwiched layers adds significant packaging complexity and increases yield losses due to chipping, contamination from dicing debris and wafer bonding adhesive that enters into the channels, wafer/polymer layer misalignment, and de-lamination of the layers. As a result of these problems, manufacturing costs are typically high.
This invention provides side shooting fluid ejection heads that do not use bonded layers to form the channel structures.
This invention separately provides side-shooting fluid ejection heads that use a sacrificial material as a mold around which structural layers are formed to provide the channel structures.
This invention separately provides a side-shooting thermal fluid ejection head that has a channel structure in which the thermal element is formed on one or more walls of structural material layers used to form the channel structure.
This invention further provides a side-shooting fluid ejection head that has a channel structure in which the thermal clement is formed to completely extend around an inner surface of the structural material layers used to form the channel structure.
This invention separately provides a side-shooting fluid ejection head that has a channel structure having a circular cross section along at least one portion.
This invention further provides aside shooting fluid ejection head that has a channel structure that has a circular nozzle opening.
This invention separately provides a fluid ejection head that has an integrated channel stricture and upstream fluid filter.
This invention separately provides methods for forming channel structures using structural material layers formed around a sacrificial material used as a mold.
This invention separately provides systems and methods of manufacturing a fluid ejection system that protects internal portions from contamination from dicing and bonding adhesives during the manufacturing process by using sacrificial mold materials.
This invention separately provides methods for forming a channel structure of a thermal side-shooting fluid ejector head having a beating element formed at least partially around an inner surface of the channel structure.
This invention separately provides systems and methods for manufacturing a fluid ejection system that is based on forming fluid micro channels on a substrate.
In various exemplary embodiments of the method of manufacturing a fluid ejection system according to this invention, channels are formed in a base substrate. In various exemplary embodiments, the channels are etched in the substrate. In various exemplary embodiments, a sacrificial material is formed in the channels and on the substrate. The sacrificial material is patterned to define a negative space that will become at least one fluid reservoir and a plurality of fluid ejection channels fluidly connected to the fluid reservoir.
In various exemplary embodiments, the fluid ejection system includes a beater element located in the fluid chamber behind the nozzle opening. In various exemplary embodiments, the geometry of the heating element is planar. In various other exemplary embodiments, the heating element is located inside the channel in either a half-cylindrical or fully-cylindrical configuration.
In various exemplary embodiments, a method of manufacturing a fluid ejector according to this invention includes a fluid filter constructed at the wafer level. In various exemplary embodiments, the fluid filter includes a layer above a fluid reservoir that is etched with a pattern of holes to produce a filter for the fluid.
These and other features and advantages of this invention are described in or are apparent from the following detailed description of various exemplary embodiments of the systems and methods according to this invention.